As for coloring PVC, you can use fabric dye such as rit mixed with clear pvc primer to dye the white pipe what ever color you would like permanently. If doing a light color just make sure to use the clear primer to remove the red lettering first if you don't want to see it.
This article also talks about adding dye to clear cleaner/primer, not sure if the dyes are toxic or not though: http://makezine.com/projects/make-30/stain-pvc-any-color-you-like/

